Callad has gone and put an idea in my head, thinking about her lighting technique has made me experiment with different room shapes. The render I have going at the moment has a cylinder base (chamfered so the walls and base join smoothly) and a half sphere as a ceiling. I'm also experimenting with bouncing a mesh light of the ceiling rather than pointing it straight at Genesis, so far it looks okay.

This render is just me playing at being a modeler, still trying to figure out the latest DS4.5 :)